Machine for boring wood.



A. E. MITCHELL.

MACHINE FOR BORING WOOD.

APPLICATION FILED MAY 26,1914.

A TTOR/VEY ALBERT E. MITCHELL, QF STAMFORD, CONNECTICUT.

MACHINE FOR BORING WOOD.

Application filed May 26, 1914.

To all whom it may concern:

Be it known that I, ALBERT E. MITCHELL, a citizen of the United States, and a resident of Stamford, in the county of Fairfield and State of Connecticut, have made and invented certain new and useful Improvements in Machines for Boring Wood, of which the following is a specification.

My invention relates to an improvement in machines for boring wood, such, for instance, as posts, beams. joists, etc, but more particularly designed for boring holes in railroad ties for the reception of screwthreaded spikes, and in which ties it is usual to provide in each end two holes approximately -3 in diameter and 63 in depth. It will of course be understood that in order to save time and labor, these four holes are usually bored simultaneously by a gang of anger bits, and further that such holes must be very accurately located or positioned, for otherwise the holes at one end of the tie will not permit the spikeheads to rest properly upon the opposite sides or edges of the base of the rail; nor permit the two rails to be properly spaced apart. I-Ieretofore in boring these ties, I have found that the bits being comparatively long, and of small diameter, frequently become bent or distorted at some point in their length, this being largely due to the fact that the wood is hard, usually oak or yellow pine, and contains knots or imperfections in the grain, causing the long and slender bits to be deflected in their passage into the wood. The result of this bending or distortion of the bit is to thereafter cause it to enter the tie to be bored at a wrong point or place, the piercing end lying to one side of the longitudinal axis of the bit. Even though the bit be but slightly bent, the point thereof will be considerably out of alinement, due to the great length of the tool. This inaccurate positioning of the holes necessitates either the scrapping of the tie, or plugging up the hole inaccurately placed, and then reboring the tie; in either event, causing a material loss of time, labor and money.

The object of my invention is to avoid this inaccurate positioning of the holes, and to so construct the machine that even though a bit be bent while in service, yet any hole which may be bored therewith or thereby, will be properly placed or positioned with relation Specification of Letters Patent.

Patented Apr. 2 0), 1915.

Serial No. 840,993.

to the other, the piercing point of the bit being properly and accurately directed to the exact spot or point in the tie to be drilled or bored, and thus avoid any and all danger of the defects above referred to.

With these and other ends in view, the invention consists in certain novel features of construction and combination of parts as will be hereinafter fully described and pointed out in the claim.

In the accompanying drawing, Figure 1 is a view in end elevation of a machine constructed in accordance with my invention. Fig. 2 is a horizontal sectional view of a portion thereof. Fig. 3 is a detached view in perspective of one of the metal guide sleeves or bushings.

In the machines which I have built and operated to eifect the results as above outlined, I have employed four drills or bits, whereby to simultaneously drill the four holes, two at the end of each tie", this machine further comprising a suitable base 5, stand ard 6, and frame 7, the latter supporting the necessary pulleys, shafting. chucks, etc, for

carrying and rotating the several bits. As

the construction and arrangement of these several parts, however, constitute no part of my invention, no detailed description or illustration thereof is essential, the gist of the invention lying in the employment of a movable support for carrying the tie and comprising a horizontal plate 8 and vertical plate 9, the length of such support being somewhat greater than the length of the tie to be drilled, and preferably made of metal. The base plate 8 is also somewhat greater in width than the tie to be supported thereon and provided on its front edge with a vertical flange 10, permitting the block or wedge 11 to be inserted between the same and the tie 12 in order to securely lock or bind the tie in position on its support. In the'vertical plate 9 are formed openings in which are fitted the bushings or metal guide sleeves 13, tightly fitting in said openings and of an internal diameter of a size to nicely contain the bit 14, these guides or bushings extending through the plate 9 and having one end or edge lying flush with the front face or surface of said plate 9, in order that the tie 12 when properly located on the support will fit against the same as illustrated in Fig. 2. The number of openings made in the plate 9 to contain these guides will depend, of course, upon the number of bits to be utilized in the machine, those which I have built and hflNe in use'einpleying four bits and consequently provided with four openings in the support, and located directly opposite those points or places where it is intended to drill the tie 12 when the latter is properly secured on the support. Into and through these guides extend the bits 14, each of which is properly held in a chuck 15 arranged in any suitable manner and adapted to be rapidly rotated.

In operation the support carrying the tie to be drilled is moved in a direction toward the bits 14, although, of course, without departing from my invention, the machine may be so arranged, if desired, as to hold the ties stationary while the bits are fed forward. In either event, the normal relative positions of the bit, bushing, and tie, are such as shown in Fig. 2, that is, the end of the bit prior to starting into the Wood, or after having. been withdrawn from such, is contained within the bushing 13, the consequence being that no matter whether the bit 14: be bent or distorted in its length, the piercing end thereof will necessarily be held in its proper position by the bushing 13 to accurately and precisely start the drilling of the tie, the bushing, in the subsequent travel of the drill into the wood, operating to properly guide the bit and temporarily straighten it if bent In the event that the bit is-bent, such will be manifested by the wear upon the bushing, whereupon the same may be removed and a new one substituted therefor, the injured or damaged bit being also replaced by a new one.

' In the use of these bushings or guides, I have constructed them of somewhat greater length than the thickness of the plate 9 in which they are supported, and prefer to make use of hardened or tempered metal, but of course do not intend to limit or restrict my claim to such, as it is evident that it may be changed or varied without in any wise departing from the spirit of my invention.

What I claim is A machine of the class described, com prising a frame, an elongated troughshaped tie support thereon, said support including horizontal and vertical plates, and a front flange, said vertical plate provided with spaced openings therein, guide sleeves disposed within said opening and extending flush with the inner face of said plate, a plurality of wood bits carried by said frame in axial alinement with said guide sleeves and. adapted to be fed forward and rotate therein, and a wedge block fitting between said tie and the front vertical flange of said support adapted to force the said tie into fixed contact with the rear face of said vertical plate.

Signed at New York, borough of Manhattan, in the county of New York and State of New York this 21st day of May, A. D. 1911-.

ALBERT E. MITCHELL.

\Vitnesses ANNA V. WALSH, GEORGE E. Coon.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

